Self-testing safety-code.



EQQQ wb. ha L NWN PATENTED SEPT. 25, 1906: o. J. MITCHELL SELF TESTING SAFETY GODE. APPL-NATION FILBD'OOT. 9, 1906.

WTNESSES:

unirsi) stares eATENT crisi/on.

CHARLES JUDGE MITCHELL, TORONTO, ONTARTO, CANADA, 'ASSIGNOR TO LILLIAN MITCHELL, OF TORONTO, ONTARIO, CANADA.

SELF-TESTING SAFETY-CODE.

Specification of Letters Patent.

Patented sept. 25, 190e.

Taiwan sied october 9,1905. serai No. asfaoes.

To @ZZ whom, t 11i/tty concern:

Be it known that I, CHARLES J L'DGE MITCH- ELL, of the city of Toronto, in the county of York, Province of' Ontario, Canada,` have invented certain nenT and useful Improvements in Self-Testing Safety-Codes, of which 4 of the message to apply one or more tests to f ing single letters or combinations of letters tached.

the codefword or Words received to 'determine probable errors in transmission; and my inventionconsists, essentially, in treatas symbols and in attaching arbitrary meanings to each symbol and in grouping the symbols in such a manner that any one symbol in the first grou taken with any one symbol from each o the other groups consecutively, Will form a coined or made and vocalizedword of a predetermined number of letters. The number of letters in the code-Word Jr'ori'ns the first test the receiver may apply to the word or Words recei ved.` A further test is provided in that as far as posl sible each section of' the code is so constructed that certain letters occurv at predetermined positions in the code-Words so madeup. For example7 it may bearranged that thevoivels occur in invariable sequence or in certain fixed positions substantially as hereinafter more specificallly described.

The drawing shows a portion of one of the d sections of a code constructed in accordance with my invention.

In the drawing I show first a column or group of symbols formed of three letters, to which symbols arbitrary meanings are at- I next show tivo columns or grou s of symbols composed of one letter eac Next a group of symbols composedof two iletters each, and next three columns or groups consecutively with any one symbol of eachv of symbols composed of single letters7 in each .and every case arbitrary meanings being attached to the said symbols. It Will further be noted that, reading from left to right, the second letter is the vovvelv E, the seventh the vowel I," and the last a consonant, and this order is maintained When any symbol from the rst column or group is combined of the other groups. It will also be seen that fore attempting to decipher the meaning.

-For instance, he first counts the number of letters. If the Word does not contain the predetermined number of lettersin the present case ten-,he knows at once that there is an error, and he may have the message repeated for correction or -possiblycorrect the error on reference to his table.

second test would be as to Whether the re- Adetermined letters or vowels occur-int eir predetermined osition. gives for the ta le in uestion't ree tests. For instance, the secon letter must be the vowel 111, the seventh the vowel I,` and the last letter a consonant. If the Word re- This practically ceived stands all these tests, the chances are in favor of the message being correct. Tt Will be found that by ,means of this system of tests at least 'fifty er cent. of possible errors in transmission Wil be detected and can be corrected on the spot Without reference to the sender.' YWith ordinary codes no such correction is possible, as, if a Word is incorrectly sent, there is no means of ascertaining What the correct Word was. Of course I do not desire lto yconiine myself to the precise arrangement of" the symbols shown, as in the construction of a complete code these will necesssarily vary Widely, both in the order of the letters employed and in the number of letters in any given symbol. The underlying principle of having each symbol in a group'coinposed of the same number of letters must be carriedthrough all. It dr s not matter, of course, what letters are' The chosen to occur in set positions in the Words coined or made up from the-tables or sections of the code, though. these areV preferably vowels but it is of course essential (and the system provides) that vowels be introduced y into these symbols, so that the Words coined or made vare vocalized. It is evident also,

EGO

that with a' code-section such as is illus-v trated the codecolumn containing instructions andreplies might be used with subsequent columns expressing articles, quantities, prices, quality, shipping instructions, or

44appear on consideration of examples .taken from the section of the code illustrated. A brokermay cable the word Rewsulidit A reference to the table shows that the wford should ycontain ten letters, that the second letter'shouldbe E, the Seventh L and the last a. consonant, andif the word stands thesetestsit isprobably correctly sent. Decoded, the Word HRewsulidit means: Would youadyise buying sevenhundred and sixty bales wool, July, twenty-two and one-half cents' Thereplyis sent lRedsuliditf whieh,decoded, means: Buy for our ac'- count and. risk,-order goodior this day only,

sevenhundred and ,sixtybales Wool, July, twenty-.two ,and one-halfcents. The origin al sender. replies: Rehsulidit ThisVdecoded,lv means: Bought f oryour account and .risk seven hundred` and sixty bales Wool,

July, twenty-two` and one-half cents. l'n each of the subsequent messages the quantity,

particulars, and price are exactly repeated,

so that absolutesafety is provided from any possible misinterpretation of the first message sent. Ordinary codes cannot provide this safeguard, as-it is impossible to providelists 'of words suilticient in number to express in con- Ilection with-the first part of the message all the possiblecombinations of information relatingthento, such as. quantity, particulars, .and price. i

It will be seen thatat the head of each column is a symbol having a series of dots 4or dashesafter it. This symbol is employed 5-A when it is Anot `desired to'.- include in a message r any Yof the information contained in that particular column.

.Fromthe above it willbeseenthat a code constructed in accordance with my invention willi'not only be much safer than those ordiunarily .mployedowin'g tof'the tests pro- .vide dbut will alsogbe more concise .and/be ,adapted to give ainuclr largerran e of Inessages. te,theconciseness,o` .the.co.de,

it saves a vast 'amount of tiniein coding and decoding messagesl over the ordinary type of code.

What I claim as my invention 1s 1. A code comprising letters and combina- .,tions of letters formingsymbols to which arbitrary meanings may be attached, the symbols being formed and grouped so that any symbol from the iirst group taken With a symbol from each of the other'g'rcupsconsecutively Will form a vocalized word containing a predetermined number of letters, substantially as described. I 'l 2. A code comprising letters and combinations of letters forming symbols to which arbitrary. meanings may be attached, the symbols beingformed and grouped so that any symbol fromthe first group taken with a symbol from each .of the other groups consecutively will form a vocalized Word certain let- ,ters used being so placed in the symbols that they each. occur in each word formed in a certain predetermined position, substantially as described.

3. A code comprising letters and combinations of letters forming symbols td which yarbitrary meanings may be attachedl, the sym- ,bols being formed and groupedl so that any symbol from the rfirst group taken with a symbol'from eachof the other lgroups consecutively will forml a vocalized Word; certain vowels used'being so placedin the symbols that they each occur in each word formed in a certain predetermined position, substantially as: described.

4. code comprising letters and combinations of letters forming symbols to which arbitrary meanings maybe attached, the symbolsqbeing formed and grouped. so that any symbol fromV the firstgroup takenwith a symbol fr m each of theother', groups consecutively will form a vocalized word containing a predetermined number of letters, certain IOO vowels used being so placed in the symbols that they each occur in each Word formed in a certain predetermined position,lsubstantially as described.

5. A code comprising letters and. combinations of letters forming symbols to which jarbitrary meanings may be attached, the symbols being formed and grouped so that any symbol from the first group taken with a symbol from each of theother groups, consecutively will forma vocalized word, substantially as described.

Toronto, October 28, 1905.

CHARLES JUDGE MITCHELL.

.Inv presence- ,of-

Manen KATE HUNTER, FRANK Ron PHILLIPS. n 

